Drosophila models using the transgenic Gal4/UAS system [2] to overexpress disease-associated aggregation-prone proteins have modeled aspects of tauopathy by overexpressing R406W mutant tau [3, 4] and Huntington's disease (HD) by overexpressing Q93httexon1 [5–7] (for review, see [8]). The gene discussed is MAPT; the disease is Huntington disease.